GoToSocial/internal/transport/dereference.go

84 lines
2.6 KiB
Go

/*
GoToSocial
Copyright (C) 2021-2023 GoToSocial Authors admin@gotosocial.org
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package transport
import (
"context"
"errors"
"fmt"
"io"
"net/http"
"net/url"
apiutil "github.com/superseriousbusiness/gotosocial/internal/api/util"
"github.com/superseriousbusiness/gotosocial/internal/config"
"github.com/superseriousbusiness/gotosocial/internal/uris"
)
// ErrGone is returned from Dereference when the remote resource returns 410 GONE.
// This is useful in cases where we're processing a delete of a resource that's already
// been removed from the remote server, so we know we don't need to keep trying to
// dereference it.
var ErrGone = errors.New("remote resource returned HTTP code 410 GONE")
func (t *transport) Dereference(ctx context.Context, iri *url.URL) ([]byte, error) {
// if the request is to us, we can shortcut for certain URIs rather than going through
// the normal request flow, thereby saving time and energy
if iri.Host == config.GetHost() {
if uris.IsFollowersPath(iri) {
// the request is for followers of one of our accounts, which we can shortcut
return t.controller.dereferenceLocalFollowers(ctx, iri)
}
if uris.IsUserPath(iri) {
// the request is for one of our accounts, which we can shortcut
return t.controller.dereferenceLocalUser(ctx, iri)
}
}
// Build IRI just once
iriStr := iri.String()
// Prepare new HTTP request to endpoint
req, err := http.NewRequestWithContext(ctx, "GET", iriStr, nil)
if err != nil {
return nil, err
}
req.Header.Add("Accept", string(apiutil.AppActivityLDJSON)+","+string(apiutil.AppActivityJSON))
req.Header.Add("Accept-Charset", "utf-8")
req.Header.Set("Host", iri.Host)
// Perform the HTTP request
rsp, err := t.GET(req)
if err != nil {
return nil, err
}
defer rsp.Body.Close()
switch rsp.StatusCode {
case http.StatusOK:
return io.ReadAll(rsp.Body)
case http.StatusGone:
return nil, ErrGone
default:
return nil, fmt.Errorf("GET request to %s failed: %s", iriStr, rsp.Status)
}
}